Navy DDG-51 and DDG-1000 Destroyer Programs: Background and Issues for Congress [August 11, 2017] [open pdf - 962KB]
"The Navy has been procuring Arleigh Burke (DDG-51) class Aegis destroyers since FY1985. The two DDG-51s requested for procurement in FY2018 are to be the 78 th and 79 th ships in the class. DDG-51s procured in FY2013-FY2017 were procured under a multiyear procurement (MYP) contract. As part of its FY2018 budget submission, the Navy is requesting authority to use another MYP contract to procure DDG-51s in FY2018-FY2022. The Navy plans to shift in FY2016 or FY2017 to a new variant of the DDG-51, called the Flight III DDG-51, that is to incorporate a new and more capable radar called the Air and Missile Defense Radar (AMDR) or the SPY-6 radar"
CRS Report for Congress, RL32109
Federation of American Scientists: http://www.fas.org/sgp/crs/index.html